=Cross build linphone and ruby=
after a while research, I found a very good library, scratchbox2, which is satisfied our needs. and the tutorial is here:

* [http://maemo.gitorious.org/scratchbox2/pages/Home home]
* [http://www.daimi.au.dk/~cvm/sb2.pdf tutorial]
* [https://wiki.merproject.org/wiki/Platform_SDK_and_SB2 tutorial]
* [http://turbosree.wordpress.com/tag/emdebian/ step by step tutorial]
* [http://www.kosagi.com/w/index.php?title=Novena/DebianBuildProcess much better tutorial]
* [https://wiki.debian.org/Multistrap#Steps_for_Squeeze_and_later have to follow those instructions]
* [http://www.emdebian.org/tools.html other tools for cross compiling]
* [https://wiki.debian.org/EmdebianGuide general guid to emdebian]
* [https://confluence.oceanobservatories.org/display/CIDev/CI+Base+Emdebian+Gumstix+Filesystem more tutorial]
* [https://launchpad.net/linaro-toolchain-binaries/+download cross tool chain]



=root file system=
emdebian can customize the linux for us, it has a list of tools, we will try to build it up from there. 

* [http://www.emdebian.org/ emdebian]

=multistrap=
* [http://www.emdebian.org/multistrap/examples.php example configuration]
* [http://www.emdebian.org/multistrap/ wiki]
* [http://www.emdebian.org/grip/ emdebian grip]
* [http://keyring.debian.org/ keyring info]
* [http://www.emdebian.org/multistrap/keyrings.html key ring auth info]
* [http://www.emdebian.org/emdebian/rootfs.html reduce rootfs size]
* [http://www.emdebian.org/crush/keys.html add key ring for sourcelist]
* [http://www.emdebian.org/baked/baked.html emdebian baked]
* [http://www.emdebian.org/grip/howto.html grid guide]

=package method=
* [http://unix.stackexchange.com/questions/30303/how-to-create-a-deb-file-manually simple method to ar to create debian]: which is working pretty well for our system